Enhanced control of flexible endoscopes through human-machine interface

ABSTRACT

An electromechanical drive system with drop-in capability allows manipulation of the majority of existing endoscopes. The invention does not require retrofitting of existing endoscopes and maintains the current clinical workflow. The drive system can be controlled through a human/machine interface, which could consist of a variety of different input devices, including a joystick, keyboard, or game controller.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a continuation of U.S. patent applicationSer. No. 13/608,487, filed Sep. 10, 2012, which claims the benefit ofpriority to U.S. Provisional Patent Application No. 61/532,916, filedSep. 9, 2011. The entire contents of each of the above applications arehereby incorporated by reference in entirety into the presentdisclosure.

FIELD OF THE INVENTION

The invention concerns the development of an integrated control/movementsystem and human/machine interface to enhance flexible endoscopy. Theinitial application considered is ureteroscopy but the invention isapplicable to numerous endoscopic procedures, including but not limitedto colonoscopy, gastroscopy, duodenoscopy, bronchoscopy,ventriculoscopy, and sinus endoscopy.

BACKGROUND OF THE INVENTION

Flexible endoscopy is a ubiquitous means of diagnosis and therapy innearly all aspects of medicine, including ureteroscopy, colonoscopy,gastroscopy, duodenoscopy, bronchoscopy, ventriculoscopy, and sinusendoscopy. Endoscopic systems from the major manufacturers are verysimilar with controls based on simple flexion of the tip of theendoscope, rotational control, and in and out translational movement.These three movements are controlled by the operator at the head of theinstrument and are all distinct in their character, making intuitivecontrol difficult to learn and perform. Efficient and safe control couldbe enhanced by a control interface that permits intuitive movements withfaithful visual feedback (e.g. when a target is identified, it can bereached smoothly). Because of the complexity of movements needed formany applications, an integrated movement/control system would have thepotential to greatly enhance the safety, efficacy, and efficiency ofthese instruments. While physicians who do endoscopy every day becomequite skilled at the contortions that can be needed for effectiveplacement of the instrument tip, the shortcomings of the currentapproach extend the time required for procedures [Harewood 2008],increase user fatigue [Berguer 2007], and have the potential to increasethe frequency of errors. For those physicians who perform endoscopy onan occasional basis, the need for a more user-friendly, intuitive meansof control becomes even more pronounced.

The basic design and functionality of all flexible endoscopes issimilar, with differences dependent upon size. Smaller instruments havesimpler but more limited control mechanisms with fewer degrees offreedom. Uretero-renoscopy is often performed with flexibleureteroscopes for access and manipulation in the ureter and kidney. Usesinclude stone removal, diagnosis for bleeding or malignancy, as well asdirect biopsy and destruction of malignant lesions. In stone disease,ureteroscopy is becoming more widely used than the other minimallyinvasive means to remove stones in both adults and children [Kerbl2002]. Ureteroscopes have improved in visual acuity and have becomesmall enough to minimize trauma and permit use in small children. Theyhave greater flexion capacity but remain controlled by the basicthree-function mechanisms. Control is performed with two hands, one tomove the ureteroscope in and out, and the other to rotate and flex theureteroscope. This leaves no hand free to perform manipulations throughthe working port, which can include stone basketing, laser lithotripsy,tumor fulguration, or biopsy. In many clinical situations, the entireinterior of the kidney must be carefully inspected to avoid leavingstone fragments or residual tumor. This requires moving the ureteroscopeinto each of the 10 to 12 calyces in the human kidney. Such delicatecontrol requires significant skill and is often challenging and slow,even for the experienced endoscopist, particularly in the lower pole ofthe kidney where the instrument must be tightly flexed and then rotatedand pulled back to move into the lower calyces.

Manipulation of the endoscope can be challenging, even for experiencedphysicians. The physician is typically watching the video image from theendoscope, while trying to navigate the anatomy. The physician must makethe mental map from the anatomy to control the endoscope, which is oftencomplex. Development of an effective and intuitive control system basedon the visual image and directionality of the endoscope would be ofgreat value in enhancing safety, efficiency, and efficacy of theseprocedures. It is well documented that more complex procedures requiremore time endoscopically and may have to be staged due to timeconstraints [Schuster 2001]. Particularly with regard to ureteroscopy,minimizing the time of the procedure is important since injury to theinterior of the kidney may occur with ongoing ureteroscope manipulationand infusion of irrigating fluid to provide a clear view. With thecomplex movements needed to direct the ureteroscope tip to a particularlocation, the orientation of the visual field changes, which disorientsthe operator and renders the combination of movements needed to achievethe required direction not intuitively apparent. The complexchoreography of movements needed to direct the ureteroscope into thevarious parts of the kidney is neither ergonomic nor efficient.

The importance of positional information through navigation has beenrecognized for many years, but there remains no clinically effectivesystem for instrument navigation in the abdomen or urinary tract. Thisimportance has been described with reference to the needs of naturalorifice transluminal endoscopic surgery (NOTES) [Rasswiler et al. 2009].Endoscopic procedures necessarily imply limitations in perception andspatial orientation of tools. Left unresolved, these limitations giverise to surgical complications. Fernández-Esparrach et al.

conducted animal studies to assess the role of CT-based navigation forNOTES. This study resulted in minor complications in 40% of standardapproach procedures, compared with 13% in procedures employingnavigation through preoperative CT-based image registration[Fernández-Esparrach et al. 2010].

Several groups have investigated navigation in flexible endoscopy, butthere is currently no commercially available system that integrates arobotic-like control system with flexible endoscopy. The Hansen Medicalrobotic catheter system (Sensei, Hansen Medical, Mountainview, Calif.)is most similar in concept, but drives a passive catheter element andrelies solely on visual feedback. Initially developed for intracardiacelectrophysiologic applications, a modified system was used to performflexible uretero-renoscopy in swine [Desai et al. 2008]. This modifiedsystem was recently extended to humans in an 18 patient study of laserlithotripsy for renal calculi [Desai et al. 2011]. This system, whilesimilar in principle, uses a steerable guide catheter and sheathassembly to control catheter placement. Limitations with such anapproach include lack of intuitive control and positional information.In summary, we are not aware of any system that provides thecapabilities of precision device manipulation proposed here by providinga “snap-in capability” for existing endoscopes as described below.

REFERENCES FOR THIS SECTION

Berguer R., M. Remler and D. Beckley, Laparoscopic instruments causeincreased forearm fatigue: A subjective and objective comparison of openand laparoscopic techniques, 1997, Vol. 6, No. 1, Pages 36-40

Desai, M. M., M Aron, I. S. Gill, G Pascal-Haber, O Ukimura, J. H.Kaouk, G Stahler, F Barbagil, C Carison, F Moll, “Flexible roboticretrograde renoscopy: Description of novel robotic device andpreliminary laboratory experience”, Urology 2008; 72: 42-46.

Fernández-Esparrach, G., R. S. J. Estépar, C Guarner-Argente, GMartínez-Pallí, R Navarro, C. R. de Miguel, H Córdova, C. C. Thompson,A. M. Lacy, L Donoso, J. R. Ayuso-Colella, A Ginés, M Pellisé, J Llach,K. G. Vosburgh, “The role of a computed tomography-based imageregistered navigation system for natural orifice transluminal endoscopicsurgery: a comparative study in a porcine model”, Endoscopy 2010;42(12): 1096-1103.

Harewood, G. C., Kristia Chrysostomou, Naila Himy and Wai Ling Leong,Impact of Operator Fatigue on Endoscopy Performance: Implications forProcedure Scheduling, Digestive Diseases and Sciences 2009, Volume 54,Number 8, 1656-166.

Kerbl, K., Rehman, J., Landman, J. et al., Current management ofurolithiasis: progress or regress? J. Endourology 16:281-8, 2002

Rassweiler, J., M Baumhauer, U Weickert, H-P Meinzer, D Teber, L-M Su,V. R. Patel, “The Role of Imaging and Navigation for Natural OrificeTranslumenal Endoscopic Surgery”, J. Endourology 2009; 23(5): 793-802.

Schuster, T G, Hollenbeck, B K, Faerber, G J, Wolf, J S, Jr.,Complications of ureteroscopy: analysis of predictive factors. J Urol166:538-40, 2001

OBJECTS AND SUMMARY OF THE INVENTION

Accordingly, one object of one or more aspects of the invention is anelectromechanical system to provide “power steering” of the endoscopefor more precise and stable control than can be achieved by the currentmethod of using a human operator.

Another objective of the method is to provide a mechanical device tostably hold the endoscope, along with a mechanism for precise actuationof translation, rotation, and tip flexion.

A related objective is to provide an electromechanical system that canbe interfaced to a variety of input devices through a human machineinterface.

A further objective of the method is to provide a general solution thatis applicable to the majority of current flexible endoscopes without theneed to retrofit the endoscope itself.

Yet another objective of the present invention is to provide a movementcontrol device that will fit conventional flexible endoscopes and permitenhanced control of the endoscope through a natural user interface thattranslates operator movements that are visually guided to endoscopemotion.

These and additional objects are accomplished by the various aspects ofthe present invention, where an existing flexible endoscope can beplaced in a mechanical platform with capabilities for actuation oftranslation, rotation, and tip flexion; the mechanical platform can becontrolled by a microprocessor-based commercially available motioncontrol card; and the system can be interfaced to a variety of userinput devices including joysticks, 6 degree of freedom mice such as theSpaceNavigator or any conventional mouse, and other input devices,including a keyboard.

Aspects of the invention in at least some embodiments include:

By providing a user interface for the control of a flexible endoscope,this system aims to enhance flexible endoscopic control, targeting,precision and safety.

Its design as a separate component that can be added to any flexibleendoscope permits this level of enhanced control without requiring thecreation and purchase of a new or different flexible endoscope.

The ability to integrate with any flexible endoscope permits applicationin a wide variety of ages, including the small endoscopes used inpediatric applications.

The familiar user interface (e.g., joystick, mouse, keyboard, otherinput device, or combination thereof) permits more natural control aswell as facilitating the operator's manipulation of any workinginstruments that are passed through the endoscope for actualmanipulation of the tissue being examined, thereby enhancing theoperative efficacy of the endoscope.

The control system will permit integration with navigational and mappingfunctions to enhance accuracy and targeting efficiency and efficacy.

The enhancements that the present invention in at least some embodimentsprovides over conventional flexible endoscopy are:

More natural user interface for endoscopic control.

Enhanced efficiency of operation for the widest user range, particularlythe non-expert.

Enhanced safety profile due to more accurate movement.

Reduced instrument damage due to more controlled application, therebyreducing costs.

Reduced radiation exposure to patient and operator due to enhancedcontrol.

The scope of use includes, but is not limited to, the following:

Urology—flexible ureteroscopy for renal stones, tumor, bleeding,surveillance for tumor, diagnosis for bleeding.

Pulmonary—flexible bronchoscopy for diagnosis and therapy of variousconditions.

Gastroenterology—upper GI endoscopy of stomach, duodenum,cholangiography, ERCP, small bowel diagnosis; lower GI endoscopy forcolonoscopy for diagnosis and treatment of tumor, polyp, screening forvarious lower GI conditions.

Otolaryngology—sinus surgery using flexible endoscopy.

Neurosurgery—ventriculoscopy for hydrocephalus and diagnosis.

All of these procedures have been widely undertaken with conventionalflexible endoscopes of differing sizes. The control systems areidentical and require the same complex manipulation for adequatecontrol. Enhancements that could potentially use conventional endoscopeshave the potential to be useful for a variety of procedures.

The advantages offered by of the present invention include, but are notlimited to, the following:

Operative Accuracy and Efficiency

Ureteroscopic efficacy is dependent upon the procedure being performed,the most common being stone extraction. Success in stone cases isheavily determined by stone location, with lower pole stones being themost challenging, and by stone size. Published stone-free rates inadults range from 31 to 90+%, with lower pole stone-free rates beingbetween 31 and 87%. Residual stone fragments are at high risk forre-growth and continued clinical morbidity. This necessitates furtherinterventions with risks and morbidity. (Matlaga and Lingeman 2012)

Pediatric stone free rates are less available due to lower incidence,but range from 50 to 87% at first treatment. Again, size and locationare critical determinants. (Cannon, Smaldone et al. 2007; Smaldone,Cannon et al. 2007; Kim, Kolon et al. 2008; Tanaka, Makari et al. 2008;Reddy and Defoor 2010; Thomas 2010; Abu Ghazaleh, Shunaigat et al. 2011;Nerli, Patil et al. 2011; Unsal and Resorlu 2011; Wang, Huang et al.2012)

Factors contributing to lack of success include inability to access thestone due to position, as well as the inability to find the stone due toinadequate navigational control. Once the stone is accessed, it must befragmented, requiring delicate positioning of the laser fiber to thestone to maximize energy transfer without injuring renal tissue. Thereis a time limit to performing ureteroscopy due to the need forirrigation and possible extravasation of irrigant and injury to thekidney and surrounding tissues, as well as cooling (particularly inchildren). Success then becomes a product of the efficiency ofidentification, access, fragmentation, and fragment removal in atime-limited procedure. Efficiency and efficacy of action are thereforethe critical determinants of success in any operator's hands.

Intra-renal stones have a lower success rate than ureteral stones.(Reddy and Defoor 2010) Lower pole stones have the lowest success ratesof intra-renal stones, largely due to the difficulty of access. (Cannon,Smaldone et al. 2007; Matlaga and Lingeman 2012)

Tumor ablation is also a time-limited procedure for similar reasons. Itis perhaps more challenging since tumor removal causes irrigantextravasation as the urothelium must be removed with the tumor. Thisneed is further enhanced as the entire collecting system must beexamined for other possible tumors, as the most common upper tract tumoramenable to ureteroscopic resection is transitional cell carcinoma, atumor with a characteristic field effect and multi-focality.(Sagalowsky, Jarrett et al. 2012)

Following initial tumor resection, continued periodic surveillance ofthe collecting system is required on a scheduled basis or in response toa positive cytology or urinary tumor marker. Such surveillance may nothave a time demand except to limit operative duration morbidity, butdemands extremely high thoroughness to avoid missing a newly developedtumor. These can be highly invasive and aggressive malignancies withlimited chemotherapeutic options.

Less frequent needs for ureteroscopy include upper urinary tractbleeding due to small vascular malformations. These lesions can beidentified and laser fulgurated but identifying them within thecollecting system in which there is no specific predilection forlocation can be difficult. Again, thorough inspection of the entirecollecting system is a critical necessity.

Operative Safety—Preventing Injury to Patient

While surgical outcome is of obvious importance, safety is an evengreater priority. Flexible ureteroscopy evolved as a safer and moreversatile alternative to the original rigid and semi-rigid ureteroscopy.Even so, flexible ureteroscopy has risks including ureteral and renalperforation, hemorrhage, and stricture. Each is preventable and would belikely reduced as risks with a more precise and efficient endoscopiccontrol system. (Reddy and Defoor 2010; Wang, Huang et al. 2011; Matlagaand Lingeman 2012; Taie, Jasemi et al. 2012)

The incidence of ureteral and renal perforation with flexibleureteroscopy is reported between 1 and 4% for all stone procedures.These can result from inaccurate use of working elements as well as theureteroscope itself. Perforation can usually be managed with stentdrainage, but requires cessation of the procedure, and may necessitate asecond procedure. The injury due to perforation, as well as overlyaggressive ureteroscope movements and longer duration procedures, cancause stricture formation. Stricture rates are reported between 0.5 to4% and can have significant short and long-term morbidity, at timesrequiring ureteral replacement. (Matlaga and Lingeman 2012) For stonecases, extrusion of the stone or fragment can occur in about 2% ofcases. The most dangerous complication is ureteral avulsion and isfortunately rare at less than 1%, but more likely in the smaller ureterof children. (Taie, Jasemi et al. 2012)

Some injuries are limited yet cause short term bleeding that reducesvisualization, necessitating premature cessation of the procedure.Failure of the initial procedure can therefore be due to relativelyminor injuries that obscure vision. It is difficult to estimate theincidence of these injuries, but may represent at least 50% of failedinitial cases of stone extraction.

Concomitant with ureteroscopy injuries is the potential for legalliability for these injuries. Endourology has been reported to generatethe most number of claims within urology, with stone cases being themost common. (Sobel, Loughlin et al. 2006; Duty, Okhunov et al. 2012)Duty reviewed the patterns of medical malpractice actions forendourology in New York State. Ureteral perforation was a recognizedaspect of these cases. Of all endourology cases, 40% were closed withindemnity at nearly $500,000 average. In the UK, Osman reported that in493 cases resulting in payment, the most commonly implicated procedurewas ureteroscopy with stenting. (Osman and Collins 2011)

Reduced Radiation Intra-Operatively

Conventional use of flexible ureteroscopy requires fluoroscopic imagecontrol for positioning and often this includes multiple images toconfirm location and to correlate scope position and the target (stoneor a particular anatomic landmark).

Estimates of radiation exposure have been published in ureteroscopy.Wieder reported exposures of 50 mGy/min of fluoroscopy. Total doses ofapproximately 560 cGy cm² have been published. (Hristova-Popova,Saltirov et al. 2011)

Only one study in children has been published but showed very highlevels of exposure. Kokorowski et al., reported high exposure with amedian skin entrance dose of 42.7 mGy (as compared to one CT scan of 10mGy), suggesting exposures equivalent to nearly 10 CT scans.(Kokorowski, Chow et al. 2012)

Reduction in fluoroscopic imaging would be accomplished by bettercontrol of the ureteroscope or ultimately by alternative navigationsystems.

Radiation to the physician is important as well and has been reported tobe in the range of 1.9 to 12 mGy depending upon body part for eachprocedure. The critical aspect is that this is an accumulative dose.(Hellawell, Mutch et al. 2005)

Reduced Damage to Endoscopes

Modern ureteroscopes are expensive to purchase and to repair. Damage toendoscopes is extremely expensive and reduces the ability of a clinicalunit to be productive if instruments are not available. (Landman, Lee etal. 2003)

Average number of uses of a modern ureteroscope is reported to bebetween 3 and 14 times, or 3 to 13 hours.

An analysis of the types of damage includes over-deflection and damageby working tools placed inappropriately. Sung et al reported that mostdamage was due to operator error and over-deflection. (Pietrow, Auge etal. 2002; Sung, Springhart et al. 2005)

Controlling the performance of the ureteroscope could potentially reducedamage and reduce costs while maintaining availability.

REFERENCES FOR THIS SECTION

Abu Ghazaleh, L. A., A. N. Shunaigat, et al. (2011). “Retrogradeintrarenal lithotripsy for small renal stones in prepubertal children.”Saudi journal of kidney diseases and transplantation: an officialpublication of the Saudi Center for Organ Transplantation, SaudiArabia22(3): 492-496.

Cannon, G. M., M. C. Smaldone, et al. (2007). “Ureteroscopic managementof lower-pole stones in a pediatric population.” Journal ofendourology/Endourological Society21(10): 1179-1182.

Duty, B., Z. Okhunov, et al. (2012). “Medical malpractice inendourology: analysis of closed cases from the State of New York.” TheJournal of urology187(2): 528-532.

Hellawell, G. O., S. J. Mutch, et al. (2005). “Radiation exposure andthe urologist: what are the risks?” The Journal of urology174(3):948-952; discussion 952.

Hristova-Popova, J., I. Saltirov, et al. (2011). “Exposure to patientduring interventional endourological procedures.” Radiation protectiondosimetry147(1-2): 114-117.

Kim, S. S., T. F. Kolon, et al. (2008). “Pediatric flexibleureteroscopic lithotripsy: the children's hospital of Philadelphiaexperience.” The Journal of urology180(6): 2616-2619; discussion 2619.

Kokorowski, P. J., J. S. Chow, et al. (2012). “Prospective measurementof patient exposure to radiation during pediatric ureteroscopy.” TheJournal of urology187(4): 1408-1414.

Landman, J., D. I. Lee, et al. (2003). “Evaluation of overall costs ofcurrently available small flexible ureteroscopes.” Urology62(2):218-222.

Matlaga, B. and J. Lingeman (2012). Surgical Management of Upper UrinaryTract Calculi. Campbell-Walsh Textbook of Urology. A. Wein, L. Kavoussi,A. Novick, A. Partin and C. Peters. Philadelphia, Elsevier, Inc. 2:1357-1410.

Nerli, R. B., S. M. Patil, et al. (2011). “Flexible ureteroscopy forupper ureteral calculi in children.” Journal ofendourology/Endourological Society25(4): 579-582.

Osman, N. I. and G. N. Collins (2011). “Urological litigation in the UKNational Health Service (NHS): an analysis of 14 years of successfulclaims.” BJU international108(2): 162-165.

Pietrow, P. K., B. K. Auge, et al. (2002). “Techniques to maximizeflexible ureteroscope longevity.” Urology60(5): 784-788.

Reddy, P. P. and W. R. Defoor (2010). “Ureteroscopy: The standard ofcare in the management of upper tract urolithiasis in children.” Indianjournal of urology: IJU: journal of the Urological Society ofIndia26(4): 555-563.

Sagalowsky, A., T. Jarrett, et al. (2012). Urothelial Tumors of theUpper Urinary Tract and Ureter. Campbell-Walsh Textbook of Urology. A.Wein, L. Kavoussi, A. Novick, A. Partin and C. Peters. Philadelphia,Elsevier, Inc. 2: 1516-1553.

Smaldone, M. C., G. M. Cannon, Jr., et al. (2007). “Is ureteroscopyfirst line treatment for pediatric stone disease?” The Journal ofurology178(5): 2128-2131; discussion 2131.

Sobel, D. L., K. R. Loughlin, et al. (2006). “Medical malpracticeliability in clinical urology: a survey of practicing urologists.” TheJournal of urology175(5): 1847-1851.

Sung, J. C., W. P. Springhart, et al. (2005). “Location and etiology offlexible and semirigid ureteroscope damage.” Urology66(5): 958-963.

Taie, K., M. Jasemi, et al. (2012). “Prevalence and management ofcomplications of ureteroscopy: a seven-year experience with introductionof a new maneuver to prevent ureteral avulsion.” Urology journal9(1):356-360.

Tanaka, S. T., J. H. Makari, et al. (2008). “Pediatric ureteroscopicmanagement of intrarenal calculi.” The Journal of urology180(5):2150-2153; discussion 2153-2154.

Thomas, J. C. (2010). “How effective is ureteroscopy in the treatment ofpediatric stone disease?” Urological research38(4): 333-335.

Unsal, A. and B. Resorlu (2011). “Retrograde intrarenal surgery ininfants and preschool-age children.” Journal of pediatric surgery46(11):2195-2199.

Wang, H. H., L. Huang, et al. (2011). “Use of the ureteral access sheathduring ureteroscopy in children.” The Journal of urology186(4 Suppl):1728-1733.

Wang, H. H., L. Huang, et al. (2012). “Shock wave lithotripsy vsureteroscopy: variation in surgical management of kidney stones atfreestanding children's hospitals.” The Journal of urology187(4):1402-1407.

BRIEF DESCRIPTION OF THE DRAWINGS

A preferred embodiment of the present invention will be set forth indetail with reference to the drawings, in which:

FIG. 1 is a block diagram of the overall system;

FIG. 2 is the same diagram showing that the system can be used without acontrol computer;

FIG. 3 is a schematic of the endoscope showing the key features;

FIG. 4 is a block diagram showing the control scheme;

FIG. 5 is the electromechanical device in which the endoscope is placed;

FIG. 6 illustrates how the endoscope can be easily inserted into theelectromechanical device;

FIG. 7 is a detailed view showing the linear platform and roll motion;

FIG. 8 is a detailed view showing the tip flexure mechanism; and

FIG. 9 is a detailed view of a guide for the endoscope shaft.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

A preferred embodiment and variations thereof will be set forth indetail with reference to the drawings, in which like elements refer tolike elements or steps throughout,

FIG. 1 illustrates the key features of the invention. The endoscope 102is manipulated by the physician Ph to the region of interest within thepatient Pt as done in current clinical practice. In the urinary tract,that would be up to the renal pelvis. The endoscope 102 is then placedin a mechanical drive system 104 that is capable of actuatingtranslation, rotation, and tip flexion degrees of freedom. Themechanical drive system 104 is connected to a motion control system 106,which enables precision actuation of those degrees of freedom. Themotion control system 106 connects to a personal computer 108 thatconnects to a human/machine interface (user input device) 110. Thephysician Ph then controls the endoscope 102 through the human/machineinterface 110. The computer 108 accepts input commands from thehuman/machine interface 108 and translates the signals to the motioncontrol system 106 to drive the motors on the mechanical drive system104. The mechanical drive system 104 holds the endoscope 102 andmechanically actuates it so the tip can be precisely controlled withinthe patient body.

FIG. 2 is the same as FIG. 1 but shows that a control computer 108 isnot necessary for this invention and instead that the human/machineinterface 110 can be connected directly to the motion control system106. The input devices can be selected based on physician preferences.Simple analog input device such as some joysticks can be connecteddirectly to the motion controller. In the case of more sophisticatedinput devices, such as those that connect through a USB interface, acomputer can serve as the interface between the input device and themotion controller 106.

FIG. 3 shows the key features of a typical endoscope 102, which can bedescribed by its three degrees of freedom: L1 is the translation of thetip 302 in and out, R2 is the rotation of the body 304 (roll), and R3 isthe rotation of the lever 306 that controls bending of the tip 302. Theport 308 for insertion of tools, the light tunnel port 310, and the CCDconnector 312 are also shown.

FIG. 4 shows the software control of the system. The user input is readin step 402 from the human/machine interface device which can be anyinput device with three or more degrees of freedom including a computermouse, keyboard, SpaceNavigator mouse, gaming controller, or othersuitable input device. The user input then undergoes a mathematicaltransformation in step 404 to put it in an appropriate format for themechanical drive system, to which the transformed user input is suppliedin step 406. The mechanical drive system then provides precision controlof the endoscope in step 408.

The physical structure of the drive system 104 is shown in FIG. 5. Themechanical drive system provides three degrees of freedom: L1 fortranslation with the linear platform; R2 for roll with the rotationmechanism; and R3 for rotation of the lever 306 to effect bending of thetip of the endoscope. In the envisioned use, the endoscope 102 is placedon the mechanical drive system 104 after the flexible end is inserted tothe region of interest within the patient, so the linear translation ofthe mechanical drive system 104 does not need to be large, and can beadequately covered by a linear platform 502. The body 304 of the scope102 can be easily inserted into the docking frame 504, which is attachedto the rotation mechanism 506 with two linear rods 7 that can be lockedin place in the rotation mechanism 506 by means of set screws or othersuitable locking mechanisms. The docking frame 504 includes a front orend docking frame 504 a that is fixed at the end of the rods and aninternal or adjustable docking frame 504 b that holds the tip flexionmechanism 508. The position of the internal or adjustable docking frame504 b that includes the tip flexion mechanism 508 can be adjusted alongthe support rods 7 by means of set screws or other suitable lockingmechanisms to accommodate scopes of varying size. The docking frame 504includes a tip flexion mechanism 508, which, when actuated, providescontrol of the flexible tip 302 of the endoscope 102. The rotationmechanism 506 is connected to the top of the linear platform 502. Whenthe rotation mechanism 506 is actuated, the scope handle and the tipflexion mechanism 508 rotate together, which provides a self-roll of theendoscope 102, shown as motion R2. When the linear platform 502 isactuated, the rotation mechanism 506 and the tip flexion mechanism 508are driven, which provides the translation L1 of the endoscope. Themotions L1, R2 and R3 of the endoscope 102 are thus actuated totally bythe mechanical drive system 104.

As shown in FIG. 6, the docking frame 504 includes U-shaped supports 6,8 and support covers 1, 2 to firmly hold the endoscope handle and body.The U-shaped supports 6, 8 are connected to the support rods 7, whichare attached to the rotation mechanism 506 of FIG. 5. The support covers1, 2 can be quickly affixed to the U-shaped supports 6, 8 through quickconnect nuts. The scope lower body adaptor 4 is incorporated within theU-shaped support 6, and together with the scope upper body adaptor 3 ofthe support cover 1, securely fixes the scope body in place. Similarly,shown on the right side, the lower body adaptor 5 within the U-shapedsupport 8, together with the specially designed support cover 2,securely fixes the other side of the scope body. Thus, the endoscope canbe easily placed and removed into and out of the docking mechanism 504.This docking mechanism 504 can be specialized for each endoscope so thatthe invention can be generalized to the majority of flexible endoscopesin use today. This docking mechanism is a passive mechanical interfacethat serves to firmly hold the scope and connect it to theelectromechanical frame. The docking mechanism can be sterilizable formultiple uses or designed as a single user device delivered in sterilepackaging. Either the docking mechanism or the rest of theelectromechanical box could be placed in a sterile bag during operatinguse to preserve a sterile field.

FIG. 7 shows the structure of the rotational mechanism and linearplatform. The base incorporates a motor 23 that drives the moving part22, which achieves the linear motion L1 in FIG. 5. The bearing 13 isfixed by the cover 14 to the rotation frame 12, which is attached to themoving part 22. The rotation shaft 11 is seated in the rotation frame 12with the bearing 13. The shaft adaptor 9 is fixed to the rotation shaft11 with screws, while the docking adaptor 24 holds the support rods 7and the support cover 9. The motor frame 16 is installed to the motorbase 18, which is assembled to the rotation frame 12. The motor 15 isattached to the motor frame 16, the connector 17 links the motor 15 andthe drive shaft 19, which is set in the motor frame 18 with a bearing20. The drive wheel 21 is attached to the drive shaft 19 and translatesthe rotation from the motor 15 to the rotation shaft 11 with a closedflexible stainless cable loop 10. Thus when the motor 15 rotates theconnector 17, the drive shaft 19, drive wheel 21, cable 10, rotationshaft 11, shaft adaptor 9, docking adaptor 24 and support rods 7 willall be rotated, which provides the rotation motion R2 in FIG. 5.

FIG. 8 shows the structure for the tip flexion mechanism 508. As shown,the motor base 35 is assembled to the tip-flexion base 31 which supportsthe support rods 7 in FIG. 5. A tip-flexion shaft 26 is installed to thetip-flexion base 31 with bearings. Shaft graspers 27 and 30 areinstalled to the tip-flexion shaft 26 with screws. The position of poles28, 29 on shaft graspers 27, 30 can be adjusted to fit and hold thelever 25 of the scope handle. The tip-flexion shaft 26 is attached tothe pulley 32, which is connected to pulley 34 by a belt 33. The pulley34 is attached to the drive shaft 36, which is installed to the motorbase 35 with bearings. The tip-flexion motor 39 is connected to themotor base 35 with a motor frame 38. A connector 37 links thetip-flexion motor 39 shaft to the drive shaft 36. Thus when thetip-flexion motor 39 rotates, the connector 37, the drive shaft 36, thepulley 34, the belt 33, the pulley 32, the tip-flexion shaft 26, theshaft grasper 27, 30 and the poles 28, 29 all rotate, and the lever 25of the scope will be rotated, which is R3 in FIG. 5. While it iscontemplated to use a cable for actuating the rotation and beltactuating the flexion, another suitable mechanical linkage such as abelt or gears can do the same.

FIG. 9 shows a guide that might be used in conjunction with themechanical drive box and could reduce the tendency for buckling of theflexible shaft 3 a of the endoscope to occur. There will be anunsupported span of flexible shaft 3 a between the point at which theflexible shaft emerges from the endoscope body 304 and the point atwhich the flexible shaft enters the patient. As a minimum, the length ofthis unsupported span must be equal to the distance by which theendoscope will be advanced after it has been placed in the patient andis ready to be inserted into the mechanical drive system. However, as apractical matter, the length of the flexible shaft will be chosen fromone of a limited set of available lengths, based on patient anatomy/sizeand the procedure to be performed, and, therefore, the unsupported spanwill be equal to the length of the flexible shaft chosen minus thedistance to which the flexible shaft has been manually advanced prior toinsertion into the mechanical drive assembly. Since the unsupported spanlength is not known a priori to a high degree of accuracy, nor preciselywhat the advancement force will be, it is desirable to have provisionfor placement of a guide 5 a at a point that is halfway or thereaboutsalong the unsupported span of the flexible shaft 3 a. The position ofthe flexible shaft guide 5 a will be adjustable to allow thepractitioner to position it at or near the halfway point of theunsupported span that arises. A swivel lock 6 a rotates out of the wayso that the flexible shaft 3 a can mount into the guide 5 a, thenswivels back to into position to capture the flexible shaft. Thecatheter is free to translate and rotate inside the guide. The effect ofthe guide 5 a is to reduce the length of the unsupported span by half,and, hence, increase the advancement force at which buckling occurs. Theguide 5 a could be easily moved out of the way, if, during advancement,it impedes further advancement. At this point, the unsupported span isshorter by a factor of two, and it is no longer needed. If the guide 5 aof FIG. 9 were to prove inadequate to prevent buckling in certainendoscopic applications, alternative means could be employed that wouldmaintain tension in the unsupported span of the flexible shaft. Forexample, a pair of opposing rollers that gently pinch the flexible shaft(as it runs between them) would be placed close to the patient entrypoint. Pre-wound rotary springs would allow the rollers to maintaintension in the flexible shaft over the span between the rollers and theemergence of the flexible shaft from the endoscope, thereby preventingbuckling.

For mechanical safety, the preferred embodiment uses limit switches oneach axis to prevent any problems with “runaway” of the controller.However, in the alternative, a slip clutch or torque limiter could beused on each axis to improve safety.

While a preferred embodiment and variations thereof have been set forthabove, those skilled in the art who have reviewed the present disclosurewill readily appreciate that other embodiments can be realized withinthe scope of the invention. For example, while the invention hasparticular relevance to ureteroscopy, it can be used for any type ofendoscopy. Also, it can be used with human or animal patients.Therefore, the present invention should be construed as limited only bythe appended claims.

We claim:
 1. A motorized system for improving manipulation of anendoscope, comprising: a mechanical device for holding and driving theendoscope; a motion control system for controlling the mechanicaldevice; and a human/machine interface for allowing a user to control themechanical device through the motion control system; wherein themechanical device comprises: a base; a linear platform for causinglinear movement of the endoscope, the linear platform being mounted onthe base to be linearly movable relative to the base; a rotationmechanism for causing rotation of the endoscope, the rotation mechanismbeing mounted on the linear platform to be movable with the linearplatform; and a tip-flexion mechanism for causing bending of the tip ofthe endoscope, the tip-flexion mechanism being mounted on the linearplatform to be movable with the linear platform.
 2. The motorized systemof claim 1, wherein the human/machine interface comprises asix-degree-of-freedom (6-DOF) controller.
 3. The motorized system ofclaim 2, wherein the 6-DOF controller comprises a mouse.
 4. Themotorized system of claim 1, wherein the linear platform comprises: amoving part mounted on the base to be linearly movable relative to thebase; and at least one support rod, extending from the moving part, onwhich the rotation mechanism and the tip-flexion mechanism are mounted.5. The motorized system of claim 1, wherein the linear platform furthercomprises at least one member for removably holding a body of theendoscope.
 6. The motorized system of claim 5, comprising at least onesaid member for removably holding the body of the endoscope, and whereinsaid at least one member for removably holding the body of the endoscopecomprises: a docking frame for holding the handle of the endoscope; anda cover panel removably attachable to the docking frame for retainingthe body of the endoscope.
 7. The motorized system of claim 6, whereinthe tip-flexion mechanism is attached to the fixed frame.
 8. Themotorized system of claim 6, wherein the rotation mechanism comprises: arotation shaft for engaging with the handle of the endoscope; a motor; adrive wheel coaxial with the motor; and a loop for conveying rotationalmovement from the drive wheel to the rotation shaft.
 9. The motorizedsystem of claim 1, wherein the tip-flexion mechanism is adapted toengage with a lever on a handle of the endoscope to actuate the lever tobend the tip of the endoscope.
 10. The motorized system of claim 9,wherein the tip-flexion mechanism comprises: a motor; an engagingelement for engaging with the lever; and a mechanical linkage forconveying movement from the motor to the engaging element.
 11. Themotorized system of claim 10, wherein the mechanical linkage comprises:a first belt pulley connected coaxially to the motor; a belt; a secondbelt pulley connected to the first belt pulley by the belt; and a shaftconnected coaxially to the second pulley; and wherein the engagingelement is on the shaft.
 12. The motorized system of claim 10, whereinthe engaging element comprises a pole.
 13. The motorized system of claim1, wherein the motion control system comprises a computer programmed toprovide automatic or semi-automatic control of the mechanical device.14. A method for using and manipulating an endoscope, the methodcomprising: (a) providing a motorized system for improving manipulationof an endoscope, the motorized system comprising: a mechanical devicefor holding and driving the endoscope; a motion control system forcontrolling the mechanical device; and a human/machine interface forallowing a user to control the mechanical device through the motioncontrol system; wherein the mechanical device comprises: a base; alinear platform for causing linear movement of the endoscope, the linearplatform being mounted on the base to be linearly movable relative tothe base; a rotation mechanism for causing rotation of the endoscope,the rotation mechanism being mounted on the linear platform to bemovable with the linear platform; and a tip-flexion mechanism forcausing bending of the tip of the endoscope, the tip-flexion mechanismbeing mounted on the linear platform to be movable with the linearplatform; (b) providing the endoscope in the device; (c) inserting theendoscope into a patient; and (d) using the motorized system tomanipulate the endoscope within the patient.
 15. The method of claim 14,wherein the human/machine interface comprises a six-degree-of-freedom(6-DOF) controller.
 16. The method of claim 15, wherein the 6-DOFcontroller comprises a mouse.
 17. The method of claim 14, wherein thelinear platform comprises: a moving part mounted on the base to belinearly movable relative to the base; and at least one support rod,extending from the moving part, on which the rotation mechanism and thetip-flexion mechanism are mounted.
 18. The method of claim 14, whereinthe linear platform further comprises at least one member for removablyholding a body of the endoscope, and wherein step (b) comprisesinserting the endoscope into the at least one member.
 19. The method ofclaim 18, wherein the at least one member for removably holding the bodyof the endoscope comprises: a docking frame for holding the body of theendoscope; and a cover panel removably attachable to the body frame forretaining the body of the endoscope.
 20. The method of claim 19, whereinthe tip-flexion mechanism is attached to the fixed frame.